Nassivera E, Nardin L
Department of Medical Physics, S. Chiara Hospital, Trento, Italy.
Br J Radiol. 1997 Jun;70(834):612-8. doi: 10.1259/bjr.70.834.9227255.
Mammography is the most reliable method by which to detect lesions in the breast. Since contrast between normal and pathological areas in the breast is extremely low, mammographic image quality should reach high standards without exceeding acceptable exposure levels for the breast. A quality control programme in mammography has been implemented. This programme is subdivided into two levels. The first consists of simple daily checks of image quality and film processing, while the second deals with more complex checks of mammographic unit, screen-film system, darkroom, illuminators, viewing conditions and reference dose determination. The values of all the parameters undergoing measurement are compared with the limiting values given by National and International Protocols. This paper describes the second level controls carried out every 6 months by the medical physicist. The parameters described are only those which have been studied and analysed in detail since the quality control programme in mammography was implemented. Such parameters (kilovoltage, focal spot dimension, half value layer, tube output, automatic exposure control system, screen-film characteristic curve and mean glandular dose) were measured during the period 1991-1995 and the results summarised. The values obtained prove the constant correct functioning of the equipment.
乳房X线摄影是检测乳腺病变最可靠的方法。由于乳腺正常区域与病变区域之间的对比度极低，乳房X线摄影图像质量应达到高标准，同时不超过乳腺可接受的照射水平。乳房X线摄影已实施质量控制程序。该程序分为两个级别。第一级包括对图像质量和胶片冲洗的简单日常检查，而第二级涉及对乳房X线摄影设备、增感屏-胶片系统、暗室、观片灯、观片条件和参考剂量测定的更复杂检查。将所有测量参数的值与国家和国际协议给出的限值进行比较。本文描述了医学物理学家每6个月进行的第二级控制。所描述的参数仅为自乳房X线摄影质量控制程序实施以来进行过详细研究和分析的那些参数。这些参数（千伏、焦点尺寸、半价层、管输出、自动曝光控制系统、增感屏-胶片特性曲线和平均腺体剂量）在1991年至1995年期间进行了测量，并对结果进行了总结。获得的值证明了设备持续正常运行。
